unleash.unleash/docs/sdks/ruby.md

id	title
ruby_sdk	Ruby SDK

Required details

• API URL – Where you should connect your client SDK
• API Secret – Your API secret required to connect to your instance.

You can find this information in the “Admin” section Unleash management UI.

    require 'unleash'

    @unleash = Unleash::Client.new(
      url: '<API url>',
      app_name: 'simple-test',
      custom_http_headers = {'Authorization': '<Client secret>'},
    )

Read more at github.com/Unleash/unleash-client-ruby